🍐 Peptide You Glossary

The biologically active component in a drug or peptide compound, the molecule that actually does the work in your body. When evaluating gray market peptides, API origin matters: domestic-sourced APIs have more verifiable chain of custody than Chinese-origin APIs. Look for COA documentation that traces the API source.

A measure of sleep apnea severity. Counts the number of breathing interruptions per hour of sleep. Normal: under 5. Mild: 5–14. Moderate: 15–29. Severe: 30+. Tracked in NextStep and relevant to anyone using CPAP therapy.

The original, FDA-approved version of a drug, manufactured by the company that developed it, like Ozempic, Wegovy, Mounjaro, or Zepbound. This is the only tier that carries full FDA approval for the specific brand name and formulation. See also Compounded and Gray Market for how the other two access tiers differ.

A method for estimating body composition, including muscle mass, fat mass, and water. A small electrical current passes through the body, fat and muscle conduct it differently. Good for trend tracking, less reliable for single-point measurement. InBody scanners use this method.

The number of calories your body burns at complete rest, just to keep organs functioning. Muscle mass significantly raises BMR, which is one of the key reasons muscle preservation during weight loss matters. Lower BMR makes weight regain more likely.

A version of an FDA-approved drug's active ingredient (like semaglutide or tirzepatide) prepared by a state-licensed compounding pharmacy, rather than the original manufacturer. Compounding has a limited, specific FDA allowance, generally tied to drug shortages or patient-specific needs, and is not the same as full FDA approval for that product. Requires a prescription. See also Branded and Gray Market.

FDA regulations governing the manufacturing environment, processes, testing, and documentation that pharmaceutical facilities must follow. A peptide supplier claiming cGMP compliance means their facility meets these standards. Third-party auditing is what separates a real claim from a marketing label.

A document from a third-party laboratory confirming the purity, potency, and identity of a compound. A COA is the primary quality signal in the gray market peptide space. Look for COAs from independent labs, not certificates issued by the seller.

The gold standard for measuring body composition, distinguishes lean mass, fat mass, and bone density with high accuracy. More reliable than BIA for single-point measurements. Requires a clinical facility.

Compounds sold as RUO (Research Use Only) outside the prescription and licensed compounding pharmacy system. Gray market products are never FDA approved, never carry an FDA-evaluated chain of custody, and require the buyer to take full responsibility for sourcing, dosing, and monitoring. Not illegal to possess, but not approved for human use. See also Branded and Compounded.

A hormone produced in the hypothalamus that signals the pituitary gland to release growth hormone. CJC-1295 is a synthetic analog of GHRH, used to stimulate the body's own GH release in a natural, pulsatile pattern.

A gut hormone that amplifies insulin release in response to food and appears to enhance fat-burning when activated alongside GLP-1. Tirzepatide activates both the GIP and GLP-1 receptors, which is why it produces greater weight loss than semaglutide alone.

A hormone naturally produced in the gut after eating. It signals the brain to reduce appetite, slows stomach emptying, and helps regulate blood sugar by stimulating insulin release. GLP-1 receptor agonists (Ozempic, Wegovy, Mounjaro, Zepbound) mimic this hormone to produce weight loss and metabolic improvement.

An FDA designation meaning that a substance is considered safe for its intended use based on scientific evidence and expert consensus. AOD-9604 holds GRAS status for food use, a meaningful safety signal, even without drug approval status for weight loss.

A blood test measuring average blood sugar over the past 2–3 months. Standard labs flag above 5.7% as prediabetic, above 6.5% as diabetic. Optimal metabolic health target: under 5.3%. A key marker in the Clarity three-lab framework alongside fasting insulin and fasting glucose.

The variation in time between successive heartbeats. Higher HRV generally indicates better autonomic nervous system health and recovery capacity. Tracked by Apple Watch and used in NextStep as a marker of sleep quality and stress recovery.

A hormone produced primarily by the liver in response to growth hormone. IGF-1 mediates many of GH's anabolic effects, muscle growth, fat metabolism, cellular repair. Relevant to the CJC-1295/Ipamorelin conversation because GH stimulation raises IGF-1.

An application submitted to the FDA before a drug can be tested in human clinical trials. Filing an IND and completing Phase I, II, and III trials is the pathway to FDA approval. Most gray market peptides have not filed an IND for their specific human therapeutic use.

The formal application submitted to the FDA after Phase III trials are complete, requesting approval to market a drug for a specific indication. A successful NDA results in FDA approval. Most peptides discussed in Peptide You have not completed this process.

The gold standard for clinical evidence. Participants are randomly assigned to treatment or placebo groups, controlling for bias. The STEP trials (semaglutide) and SURMOUNT trials (tirzepatide) are RCTs. When evaluating peptide research, ask whether the data comes from an RCT or from animal studies.

A regulatory designation meaning a compound is sold for research purposes, not for human therapeutic use. RUO compounds have not been approved by the FDA for use in humans. This is a legal posture, not a safety rating.

The total number of calories your body burns in a day, including BMR plus the energy cost of all activity. TDEE is the number that matters for weight management: eat below it and you lose weight, above it and you gain.